Tidal Disruption of Elliptical Galaxies in Rich, High-Redshift HST Clusters

44 pagesElliptical galaxy structure is widely considered to be homogenous. While they do vary in ellipticity and shape, their structure is not so varied. Or so was believed until 2015 when Schombert noticed in a study of field ellipticals that a significant percentage deviated from typical structure. These D ellipticals, as he called them, are more diffuse than traditional ellipticals. This is shown by having shallower surface luminosity profiles than the template of the same magnitude that fits normal ellipticals. In this project I have used a similar process of template fitting on galaxies within CLASH cluster environments to determine if this phenomenon exists there as well. I found that there are indeed galaxies with shallow profiles, but there is also a selection with steeper profiles. I hypothesize that the steep profiles are the result of galaxy mergers, explaining why they did not appear in the field, and that shallow profiles come from ellipticals gaining kinetic energy from interactions with the cluster’s potential well caused by elongated orbits. I also found that the templates are not a perfect match for the cluster environment but are useful for identifying tidally truncated galaxies